• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1280-1285
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• 2005

Using the nodY::lacZ fusion system in Bradyrhizobium japonicum USDA 110, 22 flavonoids, which have structurally different features, were tested to define the role of the substituted functional groups as an inducer or inhibitor for the nod gene expression. A functional ,group of 4'-OH on the B-ring and the double bond between 2-C and 3-C on the C ring were required to induce the nod gene expression in B. japonicum USDA 110. In the case of isoflavones, the 4'-methoxyl group, which blocks the open 4'-OH functional group, did not significantly lower inducing activity, as compared with isoflavones with 4'-OH. However, all flavonols tested, which have a 3-OH functional group on the C-ring, did not induce, but inhibited the nod gene expression. Flavone, 7-hydroxyflavone, and kaempferol (5,7,4'-trihydroxyflavonol) at $1\;{\mu}M$ concentration significantly inhibited the nod gene expression induced by 7,4'-dihydroxyflavone. However, 7-hydroxy-4'-methoxyflavone at $1\;{\mu}M$ concentration showed a synergistic effect with genistein and 7,4'-dihydroxyflavone on the induction activity.

• Journal of Environmental Health Sciences
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• v.18 no.2
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• pp.117-124
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• 1992

Pretreatment with low concentration of Bleomycin and Cadmium rendered Chinese Hamster Ovary Cells more resistant to the induction of chromosome aberration by subsequent high concentration of same agent, however Mitomycin C did not function in that way. The cells pre-exposed to low dose of Cadmitim did not show cross-resistance to challenge dose of Mitomycin C for the induction of chromosome aberration, but cells pre-exposed to Bleomycin showed cross resistance. And the cells pre-exposed to low dose of Mitomycin C showed cross resistance to challenge of Bleomycin, but Cadmium did not.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.10b
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• pp.188-188
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• 2003

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a prototype of halogenated aromatic hydrocarbons, is a persistent environmental contaminant and one of the most powerful tumor promoters. The molecular mechanism underlying induction of tumor promotion by TCDD has not been elucidated.(omitted)

• Molecules and Cells
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• v.39 no.10
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• pp.715-721
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• 2016

Plants have become physiologically adapted to a seasonally shifting environment by evolving many sensory mechanisms. Seasonal flowering is a good example of adaptation to local environmental demands and is crucial for maximizing reproductive fitness. Photoperiod and temperature are major environmental stimuli that control flowering through expression of a floral inducer, FLOWERING LOCUS T (FT) protein. Recent discoveries made using the model plant Arabidopsis thaliana have shown that the functions of photoreceptors are essential for the timing of FT gene induction, via modulation of the transcriptional activator CONSTANS (CO) at transcriptional and post-translational levels in response to seasonal variations. The activation of FT transcription by the fine-tuned CO protein enables plants to switch from vegetative growth to flowering under inductive environmental conditions. The present review briefly summarizes our current understanding of the molecular mechanisms by which the information of environmental stimuli is sensed and transduced to trigger FT induction in leaves.

• Journal of the Korea Safety Management & Science
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• v.5 no.2
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• pp.199-214
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• 2003

With the progress of industrial technology, industrial machinery and home appliances have multi-function and high performances by the electronic control technology. Various results are given from the measuring switching induction noise according to environmental condition and its effects cannot be predicted accurately. Therefore, the output results should be analyzed and applied to practical work. To minimize the false operation, Taguchi Method used to solve the quality problem is adopted to analyze the characteristics within the constrained measuring level.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.89-92
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• 1998

The results of chromosome aberration test in mammalian cells in culture (Chinese hamster lung fibroblast cells) showed no induction of structural and numerical aberrations by YH1226, a cephalosporin antibiotic regardless of metabolic activation, while positive control group (mitomycin C and benzo(a)pyrene) showed structural chromosome aberrations of 25% and 10%, respectively. The in vivo induction of micronuclei was measured in polychromatic erythrocytes in bone marrow of male ddY mouse given YH1226 at 500, 250, 125 mg/kg by i.p. once. After 24 hours, animals were sacrificed and evaluated for the incidence of micronucleated polychromatic erythrocytes in whole erythrocytes. Although a positive response for induction of micronuclei in animals treated with mitomycin C demonstrated the sensitivity of the test system for detection of a chemical clastogen, YH1226 did not induce microunclei in bone marrow of ddY male mice.

• Environmental Mutagens and Carcinogens
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• v.7 no.2
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• pp.103-111
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• 1987

The effects of LET (linear energy transfer) of radiation on the induction of somatic chromosome mutations or gene mutations of Drosophila melanogaster were studied. For detecting somatic chromosome mutations and gene mutations, Drosophila wing spot system and eye-color spot system were used, respectively. The frequencies of somatic chromosome mutations or gene mutations induced after third instar larval treatment with 23 MeV neutrons, thermal neutrons, X-rays were examined. From these data, the RBE(relative biological effectiveness) values of 23 MeV neutrons relative to X-rays for induction of somatic chromosome mutations or gene mutations were calculated. The present results suggest that high LET radiations are efficient than X-ray in producing not only somatic chromosome mutations but also gene mutations.

• Environmental Analysis Health and Toxicology
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• v.16 no.1
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• pp.29-34
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• 2001

The estrogenic potency of di -2-ethylhexyl phthalate (DEHP) using reverse transcriptase-PCR respouse of liver vitellogenin mRNA in male African clawed frog (Xenopus laevis) was studied. Male frogs were injected with DEHP at dose of 300$\mu\textrm{g}$/kg and 300 mg/kg body weight through the dorsal lymph sac. After 4 days, using suitable pair of RT-PCR primers, vitellogenin mRNA induction in the liver was measured and DEHP showed vitellogenin mRNA induction in only the group treated with 300 mg/kg. Any significant histological abnormalities by the exposure of DEHP was not shown in both testis and liver.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.165-170
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• 2009

Since artificial building materials and environmental contamination are getting worse recently, people has been interested in eco-friendly construction. In addition, the problems like Sick Building Syndrome are issued these days. In order to solve these problems, the reuse of building materials and the development of environment-friendly materials are urgently in demand. In this sense, Hwangtoh is in the limelight as the environment-friendly material, and broad studies on it have been in progress. However the reactivity of Hwangtoh is low, and without activation process it is very hard to use it as a building material. This study examined the usability of Hwangtoh as an environmental building material by experimenting the reactivity of inactivated Hwangtoh with Reaction Induction Material.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.64.1-64
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• 2003

Inoculation of primary pepper leaves with an avirulent strain of Xanthomonas campestris pv. vesicatoria induced systemic acquired resistance (SAR) in secondary leaves. This SAR response was accompanied by the systemic expression of defense-related genes, a systemic microoxidative burst generating H2O2, and the systemic induction of ion-leakage and callose deposition in the non-inoculated, secondary leaves. Some defense-related genes encoding PR-1, chitinase, peroxidase, PR10, thionin, defensin and zinc-finger protein were distiilctly induced in the systemic leaves. The systemically striking accumulation of H$_2$O$_2$and strong increase in peroxidase activity in pepper was suggested to contribute to the triggering of cell death In the systemic micro-HRs, leading to the induction of SAR. Treatment of non-inoculated, secondary leaves with diphenylene iodinium (DPI), an inhibitor of the oxidative burst, substantially reduced the induction of some defense-related genes and subsequently SAR.